For running safety of a vehicle, there are used radar devices for detecting objects around the vehicle. In order to ensure the detection accuracy of a radar device, it is necessary to adjust the direction of a main beam defined by the direction of a main beam, i.e. a main lobe, before shipment of the radar device or at installation of the radar device into a vehicle body.
In order to make such adjustment possible without manual work, there is a radar device capable of driving an actuator to change the inclination angle of an antenna substrate with respect to the housing of the radar device (see patent document 1); the antenna substrate means a substrate on which an antenna is formed. Specifically, the direction of the beam axis with respect to a beam output surface, i.e. a beam transmitting surface, on the antenna substrate is determined. For this reason, changing the inclination angle of the beam output surface of the antenna substrate with respect to the housing of the radar device enables adjustment of the direction of the beam axis.
Such a radar device is equipped with an inclination sensor for measuring the inclination angle of the beam output surface of the antenna substrate. The radar device is configured to control the operating quantity of the actuator according to the result of the measured results of the inclination sensor, thus adjusting the inclination angle of the beam output surface of the antenna substrate, i.e. adjusting the direction of the beam axis.